package com.zdft.promotion.common.util;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * @author Administrator
 * @date 2019/5/8
 **/
public class DateCalUtils {

    public static Date offset(Date date, int number, int offset) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(number, offset);
        return cal.getTime();
    }

    public static String format(Date date){
    	SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    	return format.format(date);
    }
    
    public static Date parse(String strDate){
    	SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    	try {
			return format.parse(strDate);
		} catch (ParseException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return null;
    }


    public static int month(Date date1,Date date2){
        int numMonth=0;
        try{
            numMonth=differentDays(date1,date2)/30;
        }catch (Exception e){
            e.printStackTrace();
            return 0;
        }
        return numMonth;
    }

    /**
     * 判断两个date2比data1多多少天
     * @param date1
     * @param date2
     * @return
     */
    public static int differentDays(Date date1,Date date2)
    {
        Calendar cal1 = Calendar.getInstance();
        cal1.setTime(date1);

        Calendar cal2 = Calendar.getInstance();
        cal2.setTime(date2);
        int day1= cal1.get(Calendar.DAY_OF_YEAR);
        int day2 = cal2.get(Calendar.DAY_OF_YEAR);

        int year1 = cal1.get(Calendar.YEAR);
        int year2 = cal2.get(Calendar.YEAR);
        if(year1 != year2)   //同一年
        {
            int timeDistance = 0 ;
            for(int i = year1 ; i < year2 ; i ++)
            {
                if(i%4==0 && i%100!=0 || i%400==0)    //闰年
                {
                    timeDistance += 366;
                }
                else    //不是闰年
                {
                    timeDistance += 365;
                }
            }

            return timeDistance + (day2-day1) ;
        }
        else    //不同年
        {
            System.out.println("判断day2 - day1 : " + (day2-day1));
            return day2-day1;
        }
    }



}
